- in a clot, platelets are held together by a mesh of a protein called "fibrin".

3) RED BLOOD CELLS - adapted to carry O2 around the body. The O2 molecule attaches to the haemoglobin protein which the red blood cells are filled with. This is how they're adapted:

- small and have a biconcave shape to give a large surface area for absorbing and releasing oxygen

- contain haemoglobin (gives blood its colour) - it contains a lot of iron. In the lungs, the oxygen reacts with the haemoglobin to form oxyhaemoglobin. In body cells, the reverse reaction happens to release oxygen into the…